new release 1.18

Signed-off-by: David Fridrich <fridrich.david19@gmail.com>

Author: gauron99

hack/build.sh

@@ -27,7 +27,7 @@ set -x
 # 1) Make a release-NN branch as normal.
 # 2) Update VERSIONS below (on main) to include the new version, and remove the oldest
 #    Order matters :-), Most recent first.
-VERSIONS=("1.17" "1.16" "1.15") # Docs version, results in the url e.g. knative.dev/docs-1.9/..
+VERSIONS=("1.18" "1.17" "1.16") # Docs version, results in the url e.g. knative.dev/docs-1.9/..
 # 4) PR the result to main.
 # 5) Party.